TROJ_REDOS.SME

 Analysis by: Roland Marco Dela Paz
 Modified by: Nice Yutuc

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes registry entries, causing some applications and programs to not function properly.

  TECHNICAL DETAILS

File Size:

200,704 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Sep 2010

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan adds the following folders:

  • %Program Files%\%SESSIONNAME%

It drops the following component file(s):

  • %Program Files%\%SESSIONNAME%\{random characters}.cc3
  • %System%\{random characters}.rdb

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Comhidserv70\Parameters
seRVicemAIN = "NPGetResourceParent"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Comhidserv70\Parameters
seRVicedlL = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ\Parameters
seRVicemAIN = "NPGetResourceParent"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
ErrorControl = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ\Parameters
ServiceDll = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"

(Note: The default value data of the said registry entry is %System%\hidserv.dll.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
Start = "2"

(Note: The default value data of the said registry entry is 4.)

It deletes the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
DependOnService = "RpcSs"

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

7.432.10

FIRST VSAPI PATTERN DATE:

03 Sep 2010

VSAPI OPR PATTERN File:

7.433.00

VSAPI OPR PATTERN Date:

04 Sep 2010

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and terminate files detected as TROJ_REDOS.SME

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
    • From: ErrorControl = "0"
      To: ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ\Parameters
    • From: ServiceDll = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
      To: ServiceDll = "%System%\hidserv.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
    • From: Start = "2"
      To: Start = "4"

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Comhidserv70\Parameters
    • seRVicemAIN = "NPGetResourceParent"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Comhidserv70\Parameters
    • seRVicedlL = "%Program Files%\%SESSIONNAME%\{random characters}.cc3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ\Parameters
    • seRVicemAIN = "NPGetResourceParent"

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System%\{random characters}.rdb

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Program Files%\%SESSIONNAME%

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_REDOS.SME. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 8

Restore this deleted registry key/value from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
    • DependOnService = "RpcSs"


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